1. Field of the Invention
The present invention relates to an image signal converting apparatus and an image display apparatus using fourth color component light in addition to red component light, green component light and blue component light.
2. Description of the Related Art
Three-plate projection image display apparatuses have heretofore been widely known, which include a red liquid crystal panel modulating a red component light, a green liquid crystal panel modulating a green component light and a blue liquid crystal panel modulating a blue component light.
To increase luminance and to reduce power consumption, proposed is a projection image display apparatus which uses fourth color component light (e.g., yellow component light) in addition to red component light, green component light, and blue component light (e.g., Japanese Patent Application Publication No. 2002-287247 (claims 1 and 4, FIG. 1 and the like)).
Specifically, in such projection image display apparatus, an improvement of the luminance of an image projected on a screen can be achieved by using yellow component light in addition to red component light, green component light and blue component light.
However, in the above-described projection image display apparatus, a mere addition of the yellow component light causes an image to be shifted to the yellow side. Thus, color reproducibility of the image is deteriorated by using the yellow component light.